De novo c.2455C>T mutation of NPR2 gene in a fetus with shortened long bones and a ventricular septal defect conceived by a mother with a fragile site at 16q22.1 and a father with a rare heterochromatic variant of chromosome 4 from Vietnam.

BACKGROUND: A heterozygous natriuretic peptide receptor 2 (NPR2) gene c.2455C>T mutation was identified as a cause of familial idiopathic short stature (ISS). Only two cases with this mutation were reported previously, and the probands with ISS had no organ system defects. METHODS: Next-generation sequencing (NGS) was performed on an amniotic fluid DNA sample of a fetus with shortened long bones and a small ventricular septal defect detected by an obstetric ultrasound examination. The pathogenic variant of the fetus was confirmed by Sanger sequencing. Sanger sequencing, G-banded, and C-banded karyotyping of the fetus's parents were subsequently performed. RESULTS: A de novo NPR2 gene c.2455C>T, p.(Arg819Cys) mutation was identified in the fetus. No microdeletion or microduplication was identified in the fetus by copy number variation sequencing with a maximum resolution of 400 kb. The two previous miscarriages experienced by the fetus's parents were interpreted as a result of chromosomal aberrations, including a maternal fragile site at 16q22.1 and a rare paternal variant involving in a large G-band-positive and C-band-positive block of paracentric heterochromatin of chromosome 4p. CONCLUSION: This report provides clinical signs of a de novo heterozygous NPR2 gene c.2455C>T mutation in the fetus and shows paternal chromosomal aberrations causing repeated pregnancy loss.

Assessment of myocardial performance index in late-onset fetal growth restriction.

The aim of this study is to determine whether the myocardial performance index (MPI) is increased in fetal growth restriction (FGR) fetuses and if increased MPI is related to adverse outcomes of FGR. This is a prospective cross-sectional study. Seventy-three late-onset FGR fetuses and 97 gestational-age matched control fetuses were enrolled in this study. Fetal blood flow parameters including MPI values were measured and compared between the two groups. For the effect of severity of growth restriction on MPI value, they were also compared with < 3rd and 3rd - 10th centile groups. FGR fetuses were divided into two groups by favorable and adverse outcome and ultrasound parameters were compared between these two groups. Moreover, significant factors related to adverse outcomes by univariate analysis were analyzed by multivariate logistic regression analysis. Pulsatility index of umbilical arterial flow (UA-PI), MPI and amniotic fluid index in the FGR were significantly different from the control fetuses. However, no significant difference between < 3rd and 3rd - 10th centile groups was detected in MPI and UA-PI. The increased levels of MPI and UA-PI were independently related with adverse outcome of late-onset FGR pregnancy. In conclusion, MPI values were increased in late-onset FGR pregnancy, and the higher level of MPI could predict adverse outcome as well as the measurement of UA-PI. Clinicians should consider cardiac dysfunction in FGR through increased MPI.